Hydraulic drill bit



Dec. 6, 1960 J. E. SMITH 2,963,102

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United States Patent HYDRAULIC DRILL BIT James E. Smith, 2717 FerndaleSt., Houston, Tex. Filed Aug. 13, 1956, Ser. No. 603,673

2 Claims. (Cl. 175-393) This invention relates in general to hydraulicdrill bits and to method of drilling. In particular, this inventionrelates to hydraulic drill bits of the rotary type for use in the oilwell drilling industry, wherein fluid or drilling mud under highpressure will drill the hole and be directed entirely through said drillbit so that it is ejected at or ahead of the mechanical cutting edge ofthe drill bit.

In the past, oil wells have been bored into the earth by means ofvarious different types of drill bits which are rotated to mechanicallybore downwardly into the earth. These bits are usually provided withsmall openings or passages therein which terminate rearwardly of themechanical cutting edges. Drilling mud under pressure is usuallydirected through said passages so that the material cut away iseventually washed upwardly and removed from the bored hole. Each of thevarious types of present conventional drill bits mechanically bores intothe earth to loosen the material which is subsequently washed upwardlyby means of the drilling mud which is forced through the passages whichterminate rearwardly of the mechanical cutting edges.

One of the principal objects of the present invention is to provide ahydraulic drill bit designed for hydraulically drilling into the earthby utilizing substantial quantities of drilling mud under high pressure.This pressure is of sufficient force to hydraulically penetrate theearth formation being drilled, which pressure is obtainable by using anew type of variable stroke variable pressure pump such as thatdescribed in my copending application Serial No. 304,935, filed August18, 1952, now US. Patent No. 2,789,515, dated April 23, 1957.

Another object of the present invention is to provide a drill bit havinga passage means therein for the drilling mud which terminates at orforwardly of the mechanical cutting edges of the drill bit. Anotherobject is to provide a hydraulic drill bit of the type described whereinthe drilling mud opening in said bit is provided with a floating pipewhich ejects said drilling mud under high pressure at a point forwardlyof said cutting edges and automatically feeds forwardly as the forwardor discharge edge of the pipe is worn away by the abrasive drilling mud.Another object is to provide an automatic feed arrangement whichutilizes the force of the drilling mud which enters the drill bit forkeeping the discharge end of the pipe at a constant distance from themechanical cutting edges regardless of the wear caused by the drillingmud. Another object is to provide a self-cleaning pipe which will notbecome clogged.

Still another object is to provide a new method of drilling wherein theactual primary drilling is accomplished by hydraulic means and themechanical cutting edges of the drill bit are provided merely to grindor chop up the material already bored out or removed so that it can bemoved upwardly out of the hole by the drilling mud and to give form toor preserve the gauge of the hole.

These and other objects and advantages will become apparent hereinafter.

The present invention is embodied in a hydraulic drill 2,963,102Patented Dec. 6, 1960 bit having an opening for drilling mud under highpressure, said opening positioned at or ahead of the mechanical cuttingedge of the drill bit. The invention is also embodied in a method ofhydraulically drilling a hole and subsequently grinding the material cutaway so that it can be washed upwardly with ease.

The invention also consists in the parts and in the arrangements andcombinations of parts hereinafter described and claimed. In theaccompanying drawings which form part of this specification and whereinlike numerals refer to like parts wherever they occur:

Fig. l is a longitudinalcross-sectional view of a hydraulic drill bitembodying the present invention,

Fig. 2 is a horizontal cross-sectional view taken along the line 2-2 ofFig. 1,

Fig. 3 is a side elevational view thereof,

Fig. 4 is a longitudinal cross-sectional view of a modified formof'hydraulic drill bit embodying the present invention,

Fig. 5 is a side elevational view of the modified bit shown in Fig. 4,and

Fig. 6 is a vertical cross-sectional view of still a furthermodification of a drill bit embodying the present invention.

Referring now to the drawings in detail, it will be seen that theembodiment of the invention which has been illustrated comprises ahydraulic drill bit 1 having an upper portion or collar 2 with athreaded shank 3 thereon for attachment to a drill collar or drill stem4 in the usual manner. The bit 1 is provided with depending mechanicalteeth 5 extending downwardly therefrom and terminating in mechanicalcutting edges 6. The bit 1 is provided with a central opening 7 having acounterbore 8 therein with a shoulder 9 therebetween having a smallradius 10 thereon to reduce strain. A smooth bore 11 is provided belowor forwardly of the counterbore 8 for slidably receiving a pipe 12having an opening 13 therein forming all or a portion of the passage 14which extends completely through the bit 1.

The pipe 12 is provided with an upper collar 15 having an upper annularsurface 16 with outwardly extending projections 16a thereon withvertical slots 17 between said projections 16a. The collar 15 is alsoprovided with a key 18 adapted to fit into a corresponding groove 19 inthe counterbore 8 so that said pipe 12 will rotate with said bit 1. Thepipe 12 has a body portion 20 extending downwardly from said collar 15which terminates in an annular bottom edge 21 which is subject toextreme wear from the earth formation and the escape of the highpressure drilling mud. The bore 11 is provided with a circumscribinggroove 22 having a seal 23 therein for preventing the passage ofdrilling mud between said pipe and the wall of said bore. An annularchamber or cavity 24 is formed in the counterbore 8 outside of the pipe12 and between the collar 15 and shoulder 9. The slots 17 connect saidcavity 24 with the counterbore 8 above said collar 15 so that nodrilling mud can become entrapped in said cavity 24 thereby preventingthe pipe 12 from moving or operating as intended. The pipe 12 is alsoprovided with internal vanes 25 which are intended to break up the earthformation that might otherwise enter therein during the drillingoperation.

In operation, the hydraulic drill bit 1 is suitably secured to the lowerend of a drilling pipe 4 and is rotated thereby. When not in contactwith the bottom of the hole, the pipe 12 hangs downwardly from the drillbit 1 with the collar 15 in substantial abutting relation with theshoulder 9. As the pressure fluid or drilling mud is directed throughand against the pipe 12 and against the material to be drilled, the pipe12 adjusts itself in said drill bit until an equilibrium position isattained.

In this equilibrium position, the bottom edge 21 of the p pe 12 isslightly below the cutting edges 6 of the drill bit as best shown inFig. l. Drilling mud is directed through passage 14, that is, throughthe counterbore 8 and opening 13 within the pipe 12, at a pressuresuflicient to hydraulically disintegrate the earth formation and boredownwardly into the earth through rock and any other material that mightbe present. Thereafter, the drilling mud is forced horizontally orlaterally outwardly from the pipe 12 after accomplishing itshydraulically drilling action. This constant movement of material whichincludes the drilling mud and the bored material, under high pressuregradually wears the lower edge 21 of the pipe 12 away, but the drillingmud acting upon the upper annular surface 16 of the collar 15 forces thepipe 12 downwardly to compensate for this wear so that the bottom edge21 of the pipe 12 remains at a distance below the mechanical cuttingedges 6.

The drilling mud with drilled material thereafter moves upwardly asshown by the arrows in Fig. l, primarily in the space 26 between themechanical cutting means and to some extent in the annular space 27 tothe top of the well, into the mud pits. The numeral 28 refers to thewall of the hole being drilled which is slightly larger than the widthof the bit 1.

After the mud with the removed material therein passes laterally beyondthe wall of the pipe 12 it is subjected to the mechanical cutting orgrinding of the teeth or cones which may be provided. As illustrated,the present invention can be used with several different types of drillbits, including those bits 1 which have only two relatively large teethas shown in Figs. 1-3, those bits 1a which have several cones 29 thereoneach having a plurality of relatively small teeth 30 as shown in Figs. 4and 5, and those bits lb which have a plurality of blades 31 such asshown in Fig. 6. With any type of drill bit, the opening or passage 14bfor the drilling mud should terminate at or have its discharge end atthe mechanical cutting edge thereof, or forwardly thereof as when thepipe 12 is used. Whenever the pipe 12 is found to be desirable, itshould preferably be suitably mounted so that it utilizes the force ofthe incoming drilling mud so as to automatically feed it forwardly tomaintain the discharge end 21 thereof at a predetermined distanceforwardly of the mechanical cutting edges 6. This is accomplished bycarefully determining the diameter of the opening within the pipe, theeffective area of the top surface 16 of the collar 15 at the upper endof the pipe 12, and the amount of hydraulic pressure necessary to borethrough the particular rock formations being drilled. For most types ofdrilling, satisfactory results will be obtained if the effective areasubject to the force of the drilling mud is substantially equal to thearea of the opening within the pipe 12. That is, referring now to Fig.2, the area of the annular surface 16 plus the area of the top of thevanes 25 should be the same as the open area 13 of the pipe 12.

Under some conditions, the pipe 12 need not be of the floating type butmay be provided with threads 32, as shown on the pipe 12a in Fig. 4,which cooperate with threads 33 in the lower portion of the centralopening 7a. With this arrangement, no counterbore 8 is necessary sincethe collar 15 has been eliminated. Thus, the passage 14a which extendscompletely through the bit 1a is of uniform diameter. Of course, thecooperating threads 32 and 33 are merely one simple form for rigidlysecuring the pipe 12a to the bit 1a and other means may be used ifdesired.

With the type of bits 1b as shown in Fig. 6, a plurality of holes 34extending angularly through the teeth or blades 31 have their loweredges 35 positioned at the cutting edges 6b of the teeth 31. This typeof bit 1b is usually provided with two or more teeth 31, each of whichmay be provided with one or more holes 34. A threaded socket 36 isprovided for receiving the externally threaded pin 37 of a drill stem38.

Obviously, the hereinbefore described hydraulic drill bit admits ofconsiderable modification without departing from the invention except asdefined in the claims. Therefore, I do not wish to be limited to theprecise arrangements shown and described.

What I claim is:

l. A hydraulic drill bit having a bore and a counterbore rearwardlythereof for receiving substantial quantitles of drilling fluid underhigh pressure, said drill bit having at least one mechanical cuttingedge for breaking up material which has been hydraulically bored, a pipeslidably mounted in said bore and having a discharge end positionedforwardly of said mechanical cutting edge, said discharge end having abottom edge positioned in a plane substantially perpendicular to thelongitudinal axis of said hydraulic drill bit, said pipe positioned toforce said drilling fluid against the bottom of the hole being drilled,said pipe having a bore of substantially uniform cross-section, saidpipe having a collar thereon slidable in said counterbore, said collarhaving at least one opening therein for establishing communicationbetween said counterbore and the space between said counterbore and saidpipe forwardly of said collar, means for locking said pipe and saiddrill bit against relative rotation, said hydraulic drill bit confiningthe hydraulic pressure against the bottom of the hole being drilled.

2. A hydraulic drill bit having a bore and a counterbore rearwardlythereof for receiving substantial quantities of drilling fluid underhigh pressure, said drill bit having at least one mechanical cuttingedge for breaking up material which has been hydraulically bored, a pipeslidably mounted in said bore and having a discharge end positionedforwardly of said mechanical cutting edge, said discharge end having abottom edge positioned in a plane substantially perpendicular to thelongitudinal axis of said hydraulic drill bit, said pipe positioned toforce said drilling fluid against the bottom of the hole being drilled,said pipe having a bore of substantially uniform crosssection, said pipehaving a collar thereon slidable in said counterbore, means for lockingsaid pipe and said drill bit against relative rotation, said collarhaving at least one opening therein for establishing communicationbetween said counterbore and the space between said counterbore and saidpipe forwardly of said collar, the effective upper annular area of saidcollar subject to the force of said drilling fluid being substantiallyequal to the area of the opening in said pipe, said hydraulic drill bitconfining the hydraulic pressure against the bottom of the hole beingdrilled.

References Cited in the file of this patent UNITED STATES PATENTS833,055 Hufimaster Oct. 9, 1906 862,972 Jones Aug. 13, 1907 1,445,289Bron Feb. 13, 1923 1,448,818 Stokes Mar. 20, 1923 2,027,063 Reifel Jan.7, 1936 2,108,955 Zublin Feb. 22, 1938 2,169,223 Christian Aug. 15, 19392,212,491 Appleby Aug. 27, 1940 2,233,260 Hawthorne Feb. 25, 19412,307,658 Appleby Jan. 5, 1943 2,540,464 Stokes Feb. 6, l 2,776,115Williams Jan. 1, 1957 FOREIGN PATENTS 296,352 Great Britain Aug. 28,1928

